emacs lisp script to tidy shellscript

shtidy.el

#!/usr/bin/env emacs --script

(defadvice message (before message-disable activate)
  "disable message function to trash stderr message"
  (ad-set-args 0 nil))

(defun insert-standard-input ()
  "insert contents from standard input"
  (condition-case nil
      (let (line) 
        (while (setq line (read-from-minibuffer ""))
          (insert line "\n")))
    (error nil)))

(defun insert-files (files)
  "insert contents from given files"
  (dolist (file files)
    (insert-file-contents-literally file)
    (goto-char (point-max))))

(defun tidy-by-alist (alist)
  "tidy by rules in given alist"
  (dolist (as alist)
    (let ((key (car as)) (value (cdr as)))
      (goto-char (point-min))
      (while (re-search-forward key nil t)
        (replace-match value)))))

(setq shell-tidyrule-alist
      '(("\\([^;]\\);\\([^;]\\)" . "\\1\n\\2")
        (" +$" . "")
        ("^ *function *" . "")
        ("\\(\\w+()\\){" . "\\1 {")
        ("\n *{" . " {")
        ("\n *then" . "; then")
        ("\n *do[^n][^e]" . "; done")
        (" *\\(|+\\) *" . " \\1 ")
        (" *\\(&+\\) *" . " \\1 ")
        ("\\S-\\\\$" . " \\\\")))

;;; main
(with-temp-buffer
  (cond (argv (insert-files argv))
        (t    (insert-standard-input)))
  (setq default-major-mode 'sh-mode)
  (set-buffer-major-mode (current-buffer))
  (untabify (point-min) (point-max))
  (tidy-by-alist shell-tidyrule-alist)
  (indent-region (point-min) (point-max))
  (princ (buffer-string)))